<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Config
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Yaml.php 24807 2012-05-15 12:10:42Z adamlundrigan $
 */
/**
 *
 * @see Zend_Config
 */
require_once 'Zend/Config.php';

/**
 * YAML Adapter for Zend_Config
 * @category Zend
 * @package Zend_Config
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Config_Yaml extends Zend_Config {

    /**
     * Attribute name that indicates what section a config extends from
     */
    const EXTENDS_NAME = "_extends";

    /**
     * Whether to skip extends or not
     * @var boolean
     */
    protected $_skipExtends = false;

    /**
     * What to call when we need to decode some YAML?
     * @var callable
     */
    protected $_yamlDecoder = array(__CLASS__, 'decode');

    /**
     * Whether or not to ignore constants in parsed YAML
     * @var bool
     */
    protected static $_ignoreConstants = false;

    /**
     * Indicate whether parser should ignore constants or not
     * @param bool $flag
     * @return void
     */
    public static function setIgnoreConstants ($flag) {
        self::$_ignoreConstants = (bool) $flag;
    }

    /**
     * Whether parser should ignore constants or not
     * @return bool
     */
    public static function ignoreConstants () {
        return self::$_ignoreConstants;
    }

    /**
     * Get callback for decoding YAML
     * @return callable
     */
    public function getYamlDecoder () {
        return $this -> _yamlDecoder;
    }

    /**
     * Set callback for decoding YAML
     * @param callable $yamlDecoder the decoder to set
     * @return Zend_Config_Yaml
     */
    public function setYamlDecoder ($yamlDecoder) {
        if ( ! is_callable ($yamlDecoder)) {
            require_once 'Zend/Config/Exception.php';
            throw new Zend_Config_Exception ('Invalid parameter to setYamlDecoder() - must be callable');
        }
        $this -> _yamlDecoder = $yamlDecoder;
        return $this;
    }

    /**
     * Loads the section $section from the config file encoded as YAML
     * Sections are defined as properties of the main object
     * In order to extend another section, a section defines the "_extends"
     * property having a value of the section name from which the extending
     * section inherits values.
     * Note that the keys in $section will override any keys of the same
     * name in the sections that have been included via "_extends".
     * Options may include:
     * - allow_modifications: whether or not the config object is mutable
     * - skip_extends: whether or not to skip processing of parent configuration
     * - yaml_decoder: a callback to use to decode the Yaml source
     * @param string $yaml YAML file to process
     * @param mixed $section Section to process
     * @param array|boolean $options
     */
    public function __construct ($yaml, $section = null, $options = false) {
        if (empty ($yaml)) {
            require_once 'Zend/Config/Exception.php';
            throw new Zend_Config_Exception ('Filename is not set');
        }
        $ignoreConstants = $staticIgnoreConstants = self::ignoreConstants ();
        $allowModifications = false;
        if (is_bool ($options)) {
            $allowModifications = $options;
        } elseif (is_array ($options)) {
            foreach ($options as $key => $value) {
                switch (strtolower ($key)) {
                    case 'allow_modifications' :
                    case 'allowmodifications' :
                        $allowModifications = (bool) $value;
                        break;
                    case 'skip_extends' :
                    case 'skipextends' :
                        $this -> _skipExtends = (bool) $value;
                        break;
                    case 'ignore_constants' :
                    case 'ignoreconstants' :
                        $ignoreConstants = (bool) $value;
                        break;
                    case 'yaml_decoder' :
                    case 'yamldecoder' :
                        $this -> setYamlDecoder ($value);
                        break;
                    default :
                        break;
                }
            }
        }
        // Suppress warnings and errors while loading file
        set_error_handler (array($this, '_loadFileErrorHandler'));
        $yaml = file_get_contents ($yaml);
        restore_error_handler ();
        // Check if there was a error while loading file
        if ($this -> _loadFileErrorStr !== null) {
            require_once 'Zend/Config/Exception.php';
            throw new Zend_Config_Exception ($this -> _loadFileErrorStr);
        }
        // Override static value for ignore_constants if provided in $options
        self::setIgnoreConstants ($ignoreConstants);
        // Parse YAML
        $config = call_user_func ($this -> getYamlDecoder (), $yaml);
        // Reset original static state of ignore_constants
        self::setIgnoreConstants ($staticIgnoreConstants);
        if (null === $config) {
            // decode failed
            require_once 'Zend/Config/Exception.php';
            throw new Zend_Config_Exception ("Error parsing YAML data");
        }
        if (null === $section) {
            $dataArray = array();
            foreach ($config as $sectionName => $sectionData) {
                $dataArray[$sectionName] = $this -> _processExtends ($config, $sectionName);
            }
            parent::__construct ($dataArray, $allowModifications);
        } elseif (is_array ($section)) {
            $dataArray = array();
            foreach ($section as $sectionName) {
                if ( ! isset ($config[$sectionName])) {
                    require_once 'Zend/Config/Exception.php';
                    throw new Zend_Config_Exception (sprintf ('Section "%s" cannot be found', implode (' ', (array) $section)));
                }
                $dataArray = array_merge ($this -> _processExtends ($config, $sectionName), $dataArray);
            }
            parent::__construct ($dataArray, $allowModifications);
        } else {
            if ( ! isset ($config[$section])) {
                require_once 'Zend/Config/Exception.php';
                throw new Zend_Config_Exception (sprintf ('Section "%s" cannot be found', implode (' ', (array) $section)));
            }
            $dataArray = $this -> _processExtends ($config, $section);
            if ( ! is_array ($dataArray)) {
                // Section in the yaml data contains just one top level string
                $dataArray = array($section => $dataArray);
            }
            parent::__construct ($dataArray, $allowModifications);
        }
        $this -> _loadedSection = $section;
    }

    /**
     * Helper function to process each element in the section and handle
     * the "_extends" inheritance attribute.
     * @param array $data Data array to process
     * @param string $section Section to process
     * @param array $config Configuration which was parsed yet
     * @return array
     * @throws Zend_Config_Exception When $section cannot be found
     */
    protected function _processExtends (array $data, $section, array $config = array()) {
        if ( ! isset ($data[$section])) {
            require_once 'Zend/Config/Exception.php';
            throw new Zend_Config_Exception (sprintf ('Section "%s" cannot be found', $section));
        }
        $thisSection = $data[$section];
        if (is_array ($thisSection) && isset ($thisSection[self::EXTENDS_NAME])) {
            $this -> _assertValidExtend ($section, $thisSection[self::EXTENDS_NAME]);
            if ( ! $this -> _skipExtends) {
                $config = $this -> _processExtends ($data, $thisSection[self::EXTENDS_NAME], $config);
            }
            unset ($thisSection[self::EXTENDS_NAME]);
        }
        $config = $this -> _arrayMergeRecursive ($config, $thisSection);
        return $config;
    }

    /**
     * Very dumb YAML parser
     * Until we have Zend_Yaml...
     * @param string $yaml YAML source
     * @return array Decoded data
     */
    public static function decode ($yaml) {
        $lines = explode ("\n", $yaml);
        reset ($lines);
        return self::_decodeYaml (0, $lines);
    }

    /**
     * Service function to decode YAML
     * @param int $currentIndent Current indent level
     * @param array $lines YAML lines
     * @return array string
     */
    protected static function _decodeYaml ($currentIndent, &$lines) {
        $config = array();
        $inIndent = false;
        while (list ($n, $line) = each ($lines)) {
            $lineno = $n + 1;
            $line = rtrim (preg_replace ("/#.*$/", "", $line));
            if (strlen ($line) == 0) {
                continue;
            }
            $indent = strspn ($line, " ");
            // line without the spaces
            $line = trim ($line);
            if (strlen ($line) == 0) {
                continue;
            }
            if ($indent < $currentIndent) {
                // this level is done
                prev ($lines);
                return $config;
            }
            if ( ! $inIndent) {
                $currentIndent = $indent;
                $inIndent = true;
            }
            if (preg_match ("/(?!-)([\w\-]+):\s*(.*)/", $line, $m)) {
                // key: value
                if (strlen ($m[2])) {
                    // simple key: value
                    $value = preg_replace ("/#.*$/", "", $m[2]);
                    $value = self::_parseValue ($value);
                } else {
                    // key: and then values on new lines
                    $value = self::_decodeYaml ($currentIndent + 1, $lines);
                    if (is_array ($value) &&  ! count ($value)) {
                        $value = "";
                    }
                }
                $config[$m[1]] = $value;
            } elseif ($line[0] == "-") {
                // item in the list:
                // - FOO
                if (strlen ($line) > 2) {
                    $value = substr ($line, 2);
                    $config[] = self::_parseValue ($value);
                } else {
                    $config[] = self::_decodeYaml ($currentIndent + 1, $lines);
                }
            } else {
                require_once 'Zend/Config/Exception.php';
                throw new Zend_Config_Exception (sprintf ('Error parsing YAML at line %d - unsupported syntax: "%s"', $lineno, $line));
            }
        }
        return $config;
    }

    /**
     * Parse values
     * @param string $value
     * @return string
     */
    protected static function _parseValue ($value) {
        $value = trim ($value);
        // remove quotes from string.
        if ('"' == $value['0']) {
            if ('"' == $value[count ($value) - 1]) {
                $value = substr ($value, 1,  - 1);
            }
        } elseif ('\'' == $value['0'] && '\'' == $value[count ($value) - 1]) {
            $value = strtr ($value, array("''" => "'", "'" => ''));
        }
        // Check for booleans and constants
        if (preg_match ('/^(t(rue)?|on|y(es)?)$/i', $value)) {
            $value = true;
        } elseif (preg_match ('/^(f(alse)?|off|n(o)?)$/i', $value)) {
            $value = false;
        } elseif ( ! self::$_ignoreConstants) {
            // test for constants
            $value = self::_replaceConstants ($value);
        }
        return $value;
    }

    /**
     * Replace any constants referenced in a string with their values
     * @param string $value
     * @return string
     */
    protected static function _replaceConstants ($value) {
        foreach (self::_getConstants () as $constant) {
            if (strstr ($value, $constant)) {
                $value = str_replace ($constant, constant ($constant), $value);
            }
        }
        return $value;
    }

    /**
     * Get (reverse) sorted list of defined constant names
     * @return array
     */
    protected static function _getConstants () {
        $constants = array_keys (get_defined_constants ());
        rsort ($constants, SORT_STRING);
        return $constants;
    }

}
